Police have praised the bravery of shoppers who intervened to confront a man who had stabbed several people in a "random attack" at a Dunedin supermarket this afternoon.
Witnesses at the scene of the multiple stabbing - at Countdown Dunedin Central about 2.35pm - said there was "chaos" as the attack unfolded.
Southern police district commander Superintendent Paul Basham told reporters police responded within minutes.
Officers found four people with stab injuries and the alleged offender, who had been detained by members of the public.
A man, who had blood on him, was arrested and was walked to the Dunedin Central Police Station, next door to the supermarket.
Supt Basham said the alleged offender was receiving medical attention in Dunedin Hospital. He was under police guard and had yet to be formally spoken to or charged.
The Southern District Health Board said five people were treated at Dunedin Hospital. Four were admitted in a serious condition - three to the ICU and one to general ward. One patient was being treated in the emergency department.
Supt Basham praised the bravery of shoppers who tried to intervene - saying they had acted selflessly and were heroic.
"The credit goes to the members of the public who acted heroically [to try and stop the alleged offender]," he said.
"This was a fast-moving and extremely traumatic event for every person in that supermarket – the victims who were injured, those present who tried to intervene and those who had to flee to a place of safety."
It was the very early stages of the inquiry, including the motivation of the attack.
"We believe this was a random attack."
The alleged offender person was likely to be formally charged this evening or tomorrow.
The minimum charge was likely to be wounding with intent to cause grievous bodily harm, he said.
Supt Basham believed the incident happened adjacent to the pharmacy in the supermarket.
The offender sustained a minor injury during the incident, he said.
"Before I came to speak to you this afternoon, I have viewed the CCTV footage which is quite traumatic. What I can say is those that intervened, some of who became injured themselves, I think have acted selfless and great courage to prevent this man from hurting anybody else - and indeed I think they did just that."
He said while the proximity of emergency services to the supermarket "undoubtedly" helped, the credit went to the members of the public who intervened.
"God forbid the status of those victims deteriorates overnight, and then we would be looking at something else. But let's hope that's not the case."
Prime Minister Jacinda Ardern said during the post-Cabinet press conference that at this stage there was nothing to suggest a domestic terror event.
Police's early assessment was that was not the case, she said.
"Needless to say such an attack is hugely concerning," she told reporters.
Ardern acknowledged courageous efforts by bystanders and said her thoughts were with all those injured.
Police had some indications of underlying factors that may have contributed, Ardern said.
She did not feel comfortable sharing those yet.
Spencer Sonn, Countdown managing director, said they were "shocked and devastated" by the incident.
"Our priority right now is our injured team members and caring for our wider team in the wake of this extremely traumatic event. We are deeply upset that customers who tried to help our team members were also injured.
"We have been concerned about the escalating violence towards our team, and this is something we have continued to talk and raise as an issue over the last year.
"Our amazing team comes to work to serve Kiwis every day, and our customers visit our stores knowing that they will be safe. We are heartbroken that this wasn't the case today.
"Our Dunedin Central store will remain closed today and tomorrow while we support our team, and we are co-operating fully with the police."
A couple, who asked not to be named, were shopping in the aisle next to the pharmacy department, where the incident took place.
"We just heard a scream and thought someone must've fallen, but it got louder and louder and more people were screaming," the woman said.
"I saw one red hand among the people; a bloody hand, and everybody started running towards the exits."
The man said members of the public had pinned the stabber down but they believed he had been able to wrestle his way free before police arrived.
Dunedin Mayor Aaron Hawkins said the incident was not something he would expect to unfold in his city.
"Everyone should feel safe in their place of work or going about everyday tasks like grocery shopping. These sorts of events are particularly chilling because it could have been any of us or our friends or family - it's a busy location in the centre of the city."
Ardern addressed the incident at her post-Cabinet press conference today.
"I have been told that there is no reason to believe that anyone else was involved.
''Needless to say such an attack is hugely concerning and I do want to acknowledge the really early reports of courageous acts by bystanders who have taken action in order to protect those around them.
''Our thoughts are with all those who have been affected by this attack."
Witnesses
One woman who was shopping a couple of aisles over, said she was also alerted to the incident by the high-pitched yelling.
"I heard screaming and I thought it was just teenagers, but then I heard someone yell 'he's got a knife'."
Another woman who was entering the supermarket at the time said she was confronted by two hysterical girls.
Another bystander grabbed them, thinking they were shoplifters but they were followed by a stampede of shoppers.
"It was chaos," she said. "Unbelievable."
Staff members were congregated outside the supermarket, some visibly shaking.
Police and multiple ambulances descended on the Cumberland St supermarket after the incident.
An Otago Daily Times reporter at the scene said one person was put into an ambulance with an apparent neck wound.
A second person was stretchered into an ambulance. At least one of the patients is a member of staff.
A third person wearing a Countdown uniform came out with a bandaged shoulder. A fourth injured person who also appeared to be a staff member was taken out of the supermarket with what looked like head and shoulder injuries.
A person at the scene said a staff member told him two other staff members had been stabbed and that the attacker allegedly walked up to someone and stabbed them in the back.
The supermarket was evacuated and people were told to stay away from the windows.
Police have blocked the entrances to the carpark but some people are being allowed to leave the carpark.
An armed police officer is standing guard outside the front entrance.
- ODT reporters/ additional reporting NZ Herald/RNZ
